Using this technique along with Virtual®XD VPS impression materials enhances the ability to precisely record the anatomy of the oral cavity and create a durable and stable impression.
Clinicians and Ceramists Utilize dental impressions to create the foundation for treatment planning and designing restorations. Impressions provide a physical and visual representation of the patient’s current dentition and an invaluable tool to dental professionals.
The dual arch impression technique captures the maxillary and mandibular impression, as well as the bite, all in one step and is ideal for several indications. It utilizes two different impressions materials: a heavy body and light body material to capture precise detail.
Utilizing this technique properly along with ideal materials ensures that accurate impressions are achieved precisely and efficiently, without the common voids, runny materials and durability issues that can negatively affect impression details.
Dual Arch Technique
Although no single technique is applicable to all treatment situations, the dual arch technique creates ideal impressions for many necessary treatments.
The following criteria should be met before selecting dual arch impression technique:
- Maximum of two prepared teeth with intact adjacent teeth should be present
- Patient should have stable dentition and ideal occlusal surface of opposing teeth
- Patient should be able to bite into maximum intercuspation without interference
- Select a rigid (preferably metal) dual arch impression tray
Together with the optimized flow of the Virtual®XD light body material and the high Shore A hardness of Virtual®XD heavy body tray material, the impression captures excellent detail reproduction that is necessary when making a dual arch impression. This combination also creates a durable and stable impression. At the same time, because it eliminates many sources of inaccuracy, it results in restorations that require no or minimal intramural adjustments.
Step 1: Prior to making impressions, place an OptraGate® lip and cheek retractor in the patient’s mouth to provide improved access to the intraoral cavity.
Step 2: Select the appropriate impression tray and evaluate the fit. Verify that the tray does not interfere with the patient’s occlusion (Fig. 1.)
Step 3: Apply Virtual® Tray Adhesive to all areas which will come into contact with the impression material, including the rims of the impression tray (Fig. 2). This will help reduce the chance of distortion when removing impressions from the mouth.
The use of adhesives in trays has also been shown to achieve higher material bond strengths than mechanical retention between the impression trays and the vinylpolysiloxane impression materials. Allow the adhesive to dry for three minutes.
Step 4: Load two cartridge dispensers, one with Virtual®XD light body wash material and one with the Virtual®XD heavy body tray material (Fig. 3). The Virtual® Mixer or a hand dispenser can be used to dispense the heavy body tray material.
Step 5: Bleed the cartridge to verify an even flow of base and catalyst from the cartridge chambers, prior to applying the mixing tip (Fig. 4).
Step 6: Load the impression tray with tray material (Fig. 5) Keep the dispensing tip buried in the material to prevent any voids or air bubbles.
Step 7: Syringe the wash material around the preparation (Fig. 6) avoid voids and air bubbles by keeping the intraoral tip buried in the material.
Step 8: Seat the tray into position (Fig. 7). Guide patient to close mouth into maximum intercuspation. Hold tray in place for the minimum set time, (two-and-a-half minutes for fast set and four-and-a-half minutes for regular set) (Fig. 8).
Step 9: Check material to verify that it is completely set and remove tray (Fig. 9).
Step 10: Rinse, dry and disinfect the final impression upon removal from the mouth. It is safe to immerse the Virtual®XD impression in a disinfection solution (e.g., glutaraldehyde 0.5% – benzalkonium chloride 0.5%) for 10 minutes without distortion.
With the variety of materials and techniques available for creating impressions available for creating impressions, determining an appropriate technique and ideal materials can be challenging. The dual arch technique can be used to capture precise and detailed maxillary and mandibular impression as well as the bite, all in one step.
The simple technique protocol ensures that accuracy and efficiency are maintained. Additionally, the Virtual®XD line of VPS impression materials from Ivoclar Vivadent provides exceptional viscosities for working with the dual arch technique. With optimized flow and advanced wetting abilities, precise details of the preparation and intraoral cavity are captured. The durable material also allows for easy disinfection and is stable up to two weeks.
Dental professionals that utilize the combined system of the dual arch technique with Virtual®XD provide their patients and ceramists with detailed and durable impressions.